Q:We have a 30' motorhome. What size wattage panel(s)do we need?

A:

Regarding the solar panels required for your motor home, the wattage depends on your intended usage and anticipated energy consumption, rather than specifically how large your RV is.  We would recommend one of our pre-packaged solar RV kits. To recharge the batteries from using inside lights and small appliances, generally an 80 watt solar panel will suffice for your RV home. You can click here then click the ‘Specs and Features' tab  to download our RV-Boat Usage Calculator to help you determine your average consumption, and size the panels accordingly. We'd be happy to help you through this process.

03-11-2010 by Gary W Category: RV and Marine

Q:Is there a consolidated source of Loans (green energy loans) that residents can use to help offset the cost of a system. I understand incentives, but they only help about 40-45 percent. I still need to come up with 37K of which I will get back another 5 k next year in taxes....all other incentives my installer will float for 12 monthes. But I am still on the line for 37K

A:

The high upfront costs is the major conundrum facing the homeowner who wants to go solar. You are right that these costs are the major impediment to growth in the residential solar market. Most homeowners will obtain a traditional home equity loan or HELOC. 

Don't let the financing blues get you down. Help is on the way.There are some new mechanisms that are available in a growing number of places around the country. Check to see if your city or county offers PACE financing. And in some states there are new solar leasing programs.

02-27-2010 by Anthony Category: Solar Panels

Q:I am working with human aid projects. I have got a question from Tanzania. They have an old 12V-freezer SANTOS SOLAR 165. I think it is like your SunDanzer 165. Question: How many 50Watt solar panels is needed to run this fridge without disturbance and what battery is needed. 

A:

There are several factors that will influence how many watts you will need to run a solar refrigerator or solar freezer. The two most important factors are the ambient air temperature and number of sunlight hours per day. In general, solar refrigerators or solar freezers require anywhere between 50-100 watts. Thus, you would need one or two 50 watt panels for your solar refrigerator or freezer to run properly. The variables outlined above would dictate the size of the battery required, but a 12V battery with 50-100 hours should provide enough reserve power for 2-3 days. We get many requests for help in designing these kinds of solar energy systems for developing countries where electricity is not readily available. And a solar freezer or fridge is an excellent solution. We would be happy design you design your system. 

02-24-2010 by Ulf E Category: Solar Outdoors

Q:What are the differences between the the various solar panel connectors and how are they chosen?

A:

Module connectors are typically connected together with external, exposed connectors. Most solar modules sold today come with MC connectors on the back of the module - MC for 'multi contact'.

There are 2 different types of MC connectors. Older connections were commonly MC Solarline 1, which is a non-locking connection. MC Solarline 2 is slightly different in that it is labeled 'DO NOT DISCONNECT UNDER LOAD', and offers a tab-and-slot mechanism to lock the connection more securely. MC2 connectors can be unlocked by hand, although there is an additional sleeve offered for MC2 connectors that requires an unlocking tool in order to separate the connection. The extra sleeve technically makes this a 3rd type of connector, although it is essentially an MC2 connection.

The primary requirement of all solar connectors is that they meet the NEC Code, specifically article 690.33.

01-08-2010 by Larry L Category: Solar Panels

Q:I am looking for lighting that can be used to accent building features at night. Do I want spot or flood? Are any of the solar lights bright enough?

A:

The choice between solar spot light and solar flood light in this instance is a matter of preference. If you want a more focused beam of light that illuminates a building feature or flag, use a solar spot light. If you are looking to provide general ambient lighting that diffuses light, use a solar flood light. Solar lights come in a variety of outputs and wattages depending on the amount of light you are looking for and the size of the space you are illuminating. If you want simple ambient lighting, the smaller contained systems work well for most home settings. However, if you are attempting to brightly light a sign or large building, solar commercial lights that have higher bulbs and larger solar cells may be what you need. The price range on these items can really vary depending on lighting specifications.

12-15-2009 by Kathleen L Category: Solar Lights and Garden

Q:we are interrested in solor film panels. and would like to know how much voltage out put they have say per foot?

A:

Thanks for your question. Thin film solar panels have a lower efficiency output (6-8%) versus that of conventional PV modules (11-18%). When you ask about voltage per foot, I think what you really want to know is wattage per square foot. Wattage=volts X amps. A good way to think about this is like water in a pipe system. Volts are the force or "pressure" of the electrical current, and amps is the volume of current. Watts is total electrical output. To answer your question then, thin film panels generate between 6-8watts per square foot. By comparison PV modules produce 15-20watts per square foot.

11-23-2009 by Art C Category: Solar Panels

Q:How much would it cost to install 30,00 panels to the Grid? How would I begin?

A:

30,000 panels or 30,000 watt system?

30,000 panels would be an industrial sized solar array, generating roughly 6MW of power and would cost upwards of $15 million. A 30 kW system, although still quite large, could be deployed on a warehouse roof or on ground mounts. For the solar panels alone, it would cost you roughly $2.50 - $3.00 per watt or more depending on the efficiency of the modules. With the installation costs, which can vary widely throughout the country, and other requisite solar equipment to run the solar array, the per watt price may be in the $5.00 - $7.00 range. Consequently, it would cost $125,000 or more for this size installation. Currently there are a whole slew of federal and state rebate programs to help bring the installer's cost down, as much as 50% of the upfront costs. Most homeowners in the US achieve 85-100% of their requisite power needs by installing a 5 - 7 kW system. The cost for this would run between $20,000 - $30,000, but would receive federal tax credits and state, local or utility rebates. 

11-11-2009 by melissa Category: Solar Panels

Q:I'm looking to put together a system that can output 120V 10amp, Max 1200W. what do I need?

A:

I am assuming this is not a stand-alone/off-grid system, but simply how many panels will output this much energy? Watts are instantaneous power, and Watt-Hrs are like your car's speedometer. How fast are you going if you're travelling at 60mph? Watt-hrs is as important as instantaneous power.

If you need 1200 watts all at once for 24-hrs/day, then you'd need six 200-watt rated panels and these would only output this much energy during peak sun hours. So the next question is 1200 watts for how long? If you're connected to the grid and just want to offset 1200 watts of AC, then 1 panel could generate 1200 watt-hrs of energy with 6 hrs of sun.

That's the beauty of being ‘grid-tied' - the grid is essentially your battery. When you're not using that 1200-watt bulb, you're sending that energy to your account!  We would be happy to help you spec a system.

11-06-2009 by JayS Category: Solar Panels

Q:I was wanting to have a solar array to offset my power usage. here in alabama if you want to particapate in net metering you must carry one million dollars in liabilaty insurance. so... i was wondering if the system could be wired into my home to provide power to my home only. if i buy the requiered ammount of insurance i will not make anything from net metering, but instead of the meter turning backwards i would be happy if it just stopped turning. i thought about installing stand alone outlets but would rather wire it into my home and stop the meter from turning. could this be done?

A:

Thank you for your question - the best approach I believe you have is to build a separate system, such that you turn off the main breaker on your primary (grid connected) electric panel. That will stop it from turning. People have been living off the grid for years, using solar modules + batteries + inverters. The best means to stop your meter from turning without doing net metering is to turn the panel OFF. If you run a solar system through it, it will spin forwards and backwards depending on power generation and consumption - you'll be doing net metering, whether your utility supports it or not.

I have not heard of the liability requirement for residential systems, though I suspect it is an outdated requirement to ensure that no power is pushed onto the grid when a blackout situation has occurred. Fortunately commercially available inverters shut down in a grid-tie setup for this very reason. When there is a blackout your solar system is down too, so that lineman can fix the blackout problem without getting zapped by different ‘island' solar systems.

Answer Updated:

FOLLOW-UP Note that you do not need to carry $1M liability is no longer required by Alabama Power - I did a bit of legwork and got this response from the Alabama Dept. of Economic and Community Affairs. "The $1M liability policy is no longer required by Alabama Power. The metering however is not net metering. APCo requires 2 meters, one for flow each way. The customer buys power at retail and sells his excess power at wholesale."

Since you do not need to carry this policy hopefully it will be more affordable for you to pursue a grid-tie system!  We would be please to assist you picking out the the solar panels and other components for your PV system.

11-03-2009 by KerryM Category: Solar Panels

Q:recently i observed peel& stick rolls of solar panels about 12" wide by 20' long producing about 40v can you find & sell me this?

A: 

Thank you for your inquiry. I believe what you saw were thin film panels. We carry the top of the line thin film strips manufactured by a company called Unisolar. They are 15.5' inches wide and 16.4ft long, and come in a variety of wattages. Currently we offer the 68w, 124w, and 136w. They can be found on the link embedded above. Please give us a call if you have any further questions.

11-02-2009 by VernonP Category: Solar Panels